The process of developing large quantifies of photographic materials involves the mixing of chemical substances supplied in the form of concentrates to produce a usable processing fluid. The concentrates used may be supplied in solid or liquid form. A known apparatus for emptying such chemical concentrates from their containers or bottles into a mixing tank is described by DE-GM 89 09 792, for example. The necks of the containers are inserted in holders so that the concentrate runs out of the container by the force of gravity into a collecting trough and from there into a measured-delivery tank.
In order that critical concentrations are not created as the concentrates are being mixed, the order in which the various constituents are added should be carefully considered or strictly controlled. DE-GM 91 02 722 describes an emptying/holding apparatus for this purpose by means of which a locking mechanism only allows the chemical containers to be inserted in the holders in the desired specified sequence, the emptying of the chemical containers, however, being once again effected by the force of gravity.
Such methods/apparatuses do not ensure that all chemical residues are removed from the containers. Particularly in the case of liquid concentrates, residues remain behind in the containers despite employment of suitably long dwell times for the liquid to empty out of the containers, with the result that they can not be disposed of without first passing through an additional rinsing process. The separate rinsing stage firstly requires additional work and equipment while secondly, the solution obtained from the rinsing process can not be fed back into the processing cycle without further treatment due to its generally indeterminate concentration.